Question

How do you combine like terms in `(3x ^ { 2} + 5y ^ { 2} - 2) - ( x ^ { 2} + 5y ^ { 2} - 4)`?

Answer 1

`2x^2+2`

Explanation:

The negative in front of the 2nd parentheses makes everything in it negative. Nothing in front of the parentheses means that you have a 1 in front of it. But since a 1 does nothing to the numbers as of now, you just take away the parentheses. So
`(3x^2+5y^2-2)-(x^2+5y^2-4)`
becomes
`3x^2+5y^2-2-x^2-5y^2+4`

And then all the numbers with the same letter at the back are added or subtracted to each other depending on their signs.

Reorginized
`3x^2-x^2+5^2-5y^2-2+4=2x^2+2`